Cyclists are not known for having the most robust of arms. So when the temps go down, it's important to keep them warm. The Nashbar Thermal Arm Warmers make it easy to take the freeze out of your frail upper appendages without resorting to drastic measures like long sleeve jerseys.

I wear size small in all shirts, jackets, sweaters etc. Size small in these arm warmers are super tight but that's the whole point. Use these warmers on my early morning bike ride and take them off as I heat up. Great arm warmers for the price. Doesn't slide and seems like it's made from good quality

Haven't used them yet so I can't comment on durability, but I can comment on size and they fit great. I ordered a pair in size medium. Just the right length and comfortably snug without being tight/restricting. I'm 5'6" & 153 lbs. My arms from the tops of my shoulders to my wrist are about 21 inches. I have 13 inch biceps.

Bought these to replace a pair with worn grippers. Got the old ones from Nashbar years ago. Old ones were made in USA and medium fit just right. The new ones are made in China; upper diameter is 2" smaller, lower diameter is 1-1/2" smaller. I am exchanging mediums for large.

I read someone's review that said they ran big & suggested ordering med size, so as a regular guy, (no weight lifting, etc.) I got the mediums, they are too small, my right bicep measure 11.5 inches, I hope that helps other gauge their proper size.

There is no need to spend a lot more for arm warmers. The differences in materials is negligible. Having a silicone gripper at the top is useful to help keep them in place. I ordered a size lower this time. Really tight, but I think as they wear they will be more likely to stay in place.